CSV encode to ByteBuffer?

[javafanboy]

I would like to CSV Encode records of data to a ByteBuffer without any buffering that when the buffer reaches a specific size it will go through other processing steps like compression, BASE64 encoding and transmission that all work on ByteBuffers.
I can see that fast CSV integrates with StringWriter but I would for performance reasons like to "leave Strings behind" and work with ByteBuffer instead.
Any thoughts on if this is possible and in that case how? I would not mind subclassing the writer class etc. - just looking for advice on the best performing and simplest way yo do this...

[osiegmar]

I can see that fast CSV integrates with StringWriter

A StringWriter is usually used for demonstration purposes only. The usual use pattern (write to a CSV file) is based on an OutputStreamWriter (see CsvWriter.CsvWriterBuilder#build(java.nio.file.Path, java.nio.file.OpenOption...)).

Any thoughts on if this is possible and in that case how?

You may simply try it by changing the implementation of CsvWriter.FastBufferedWriter to use a ByteBuffer/CharBuffer instead of a char[] buf and a WritableByteChannel instead of a Writer.

Then do extensive JMH benchmarks.